diff --git a/lib/contracts/erc8004.ts b/lib/contracts/erc8004.ts
new file mode 100644
index 00000000..f4b6f34d
--- /dev/null
+++ b/lib/contracts/erc8004.ts
@@ -0,0 +1,46 @@
+import { type Address } from "viem";
+import { publicClient } from "../viem";
+import { ERC8004_REGISTRY } from "./constants";
+
+/**
+ * Minimal ABI for ERC-8004 Agent Registry — reverse lookup by wallet.
+ *
+ * `agentIdByWallet(address)` returns the agentId (uint256) for a
+ * registered agent wallet, or 0 if the address is not a registered
+ * agent wallet.
+ */
+const erc8004Abi = [
+  {
+    type: "function",
+    name: "agentIdByWallet",
+    stateMutability: "view",
+    inputs: [{ name: "wallet", type: "address" }],
+    outputs: [{ name: "agentId", type: "uint256" }],
+  },
+] as const;
+
+/**
+ * Check if an address is a registered ERC-8004 agent wallet.
+ *
+ * Returns the writer_type value:
+ *   0 = human (not a registered agent wallet, or query failed)
+ *   1 = agent (registered agent wallet with agentId > 0)
+ *
+ * Best-effort: defaults to 0 (human) on any error.
+ */
+export async function detectWriterType(
+  writerAddress: Address
+): Promise<number> {
+  try {
+    const agentId = await publicClient.readContract({
+      address: ERC8004_REGISTRY,
+      abi: erc8004Abi,
+      functionName: "agentIdByWallet",
+      args: [writerAddress],
+    });
+    return agentId > BigInt(0) ? 1 : 0;
+  } catch {
+    // Best-effort: default to human if registry query fails
+    return 0;
+  }
+}
diff --git a/src/app/api/index/storyline/route.ts b/src/app/api/index/storyline/route.ts
new file mode 100644
index 00000000..1de941f9
--- /dev/null
+++ b/src/app/api/index/storyline/route.ts
@@ -0,0 +1,115 @@
+import { NextResponse } from "next/server";
+import { type Hex, decodeEventLog, encodeEventTopics } from "viem";
+import { publicClient } from "../../../../../lib/viem";
+import { createServerClient } from "../../../../../lib/supabase";
+import {
+  storyFactoryAbi,
+  storylineCreatedEvent,
+} from "../../../../../lib/contracts/abi";
+import { detectWriterType } from "../../../../../lib/contracts/erc8004";
+import type { Database } from "../../../../../lib/supabase";
+
+/** StorylineCreated event topic0 */
+const STORYLINE_CREATED_TOPIC = encodeEventTopics({
+  abi: [storylineCreatedEvent],
+  eventName: "StorylineCreated",
+})[0];
+
+function error(message: string, status = 400) {
+  return NextResponse.json({ error: message }, { status });
+}
+
+export async function POST(req: Request) {
+  const body = await req.json();
+  const txHash = body.txHash as Hex | undefined;
+
+  if (!txHash || !/^0x[0-9a-fA-F]{64}$/.test(txHash)) {
+    return error("Missing or invalid txHash");
+  }
+
+  // 1. Fetch receipt
+  let receipt;
+  try {
+    receipt = await publicClient.getTransactionReceipt({ hash: txHash });
+  } catch {
+    return error("Failed to fetch transaction receipt", 502);
+  }
+
+  if (receipt.status !== "success") {
+    return error("Transaction failed");
+  }
+
+  // 2. Find StorylineCreated event log by event signature (topic0)
+  const storylineLog = receipt.logs.find(
+    (log) => log.topics[0] === STORYLINE_CREATED_TOPIC
+  );
+
+  if (!storylineLog) {
+    return error("StorylineCreated event not found in receipt");
+  }
+
+  // 3. Decode event
+  let decoded;
+  try {
+    decoded = decodeEventLog({
+      abi: storyFactoryAbi,
+      data: storylineLog.data,
+      topics: storylineLog.topics,
+    });
+  } catch {
+    return error("Failed to decode StorylineCreated event");
+  }
+
+  if (decoded.eventName !== "StorylineCreated") {
+    return error("Unexpected event type");
+  }
+
+  const { storylineId, writer, tokenAddress, title, hasDeadline } =
+    decoded.args;
+
+  // 4. Get block timestamp
+  let blockTimestamp: bigint;
+  try {
+    const block = await publicClient.getBlock({
+      blockNumber: receipt.blockNumber,
+    });
+    blockTimestamp = block.timestamp;
+  } catch {
+    return error("Failed to fetch block", 502);
+  }
+
+  // 5. Detect writer type via ERC-8004 (best-effort, defaults to human)
+  const writerType = await detectWriterType(writer);
+
+  // 6. Upsert to Supabase
+  const supabase = createServerClient();
+  if (!supabase) {
+    return error("Supabase not configured", 500);
+  }
+
+  const row: Database["public"]["Tables"]["storylines"]["Insert"] = {
+    storyline_id: Number(storylineId),
+    writer_address: writer.toLowerCase(),
+    token_address: tokenAddress.toLowerCase(),
+    title,
+    plot_count: 1, // genesis plot
+    has_deadline: hasDeadline,
+    writer_type: writerType,
+    last_plot_time: new Date(Number(blockTimestamp) * 1000).toISOString(),
+    block_timestamp: new Date(Number(blockTimestamp) * 1000).toISOString(),
+    tx_hash: txHash.toLowerCase(),
+    log_index: storylineLog.logIndex!,
+  };
+
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  const { error: dbError } = await (supabase.from("storylines") as any).upsert(
+    row,
+    { onConflict: "tx_hash,log_index" }
+  );
+
+  if (dbError) {
+    return error(`Database error: ${dbError.message}`, 500);
+  }
+
+  return NextResponse.json({ success: true });
+}